The present disclosure relates to a method for storing traffic data in a database for use by a navigation system. In particular, it relates to a method of differentiating traffic data obtained by navigation systems in probe vehicles for storage at a remote server in a carpool lanes database and a regular lanes database.
Navigation systems are well known in the industry. Navigation systems typically calculate a route from the location of the system to a desired location input by a user. Many navigation systems use a traffic database to determine travel times and traffic incidents along a route. The navigation system may calculate a route based on the data contained in the traffic database, and the navigation system directs the user via that route.
Typically, a traffic database associates individual segments of a route with travel times and other traffic incident data collected from multiple probe vehicles traveling along that route. The traffic database may be stored in a database for use by a navigation system in calculating a route to a desired location.
In many areas of the country, carpool lanes form an integral part of the transportation system. In the Los Angeles area, for example, almost every major interstate route includes at least one carpool lane (often called an HOV or High Occupancy Vehicle lane). In the Washington, D.C. metro area, there are entire stretches of interstates that become HOV lanes at certain times of the day. In addition, in Washington, D.C. and Houston, the HOV lanes are accessible only at certain times of the day and are shared, such that they are open to traffic in one direction during certain hours and to traffic in another direction during other hours. In some cases, however, the use of the HOV lanes may be undesirable. For example, in Houston and Washington, D.C., the HOV lanes are separated from other lanes of traffic. Accordingly, if an accident occurs in an HOV lane, it may be impossible to bypass the accident and the HOV lane may be much slower. It is desirable to calculate alternate travel times for a user considering various routes that do and do not use the HOV lanes.
Accordingly, there is a need in the art for a traffic database that differentiates between traffic data collected for regular lanes and traffic data collected for carpool lanes.